In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (dа ta: H₂O (l) → H₂O (g) ΔH = 44.01 kJ/mol.) A. 315g of water vapor was produced. B. 17.5 g of water vapor was producedC. 17.5 mol of water vapor was produced. D. 17.5 mol of liquid water was produced. E. 17.5 g of liquid water was produced.

Question

Chemistry

Dirty Harry

5 May, 21:44

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (dа ta: H₂O (l) → H₂O (g) ΔH = 44.01 kJ/mol.) A. 315g of water vapor was produced. B. 17.5 g of water vapor was producedC. 17.5 mol of water vapor was produced. D. 17.5 mol of liquid water was produced. E. 17.5 g of liquid water was produced.

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Answers (1)

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Cassie Holden · Answer 1

A

Explanation:

To calculate this, we first need to know the number of moles of water vapor that was produced. This can easily be obtained by dividing the amount of energy released by the enthalpy change I. e n = E/ΔH

This will yield a value of 770.1/44.01 = 17.5 moles

Now, to calculate the mass of water vapor produced, we simply multiply the number of moles by the molar mass of water. The molar mass of water is 18g/mol and the mass is thus 17.5 * 18 = 315g of water vapor